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Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications
Published on: February 23, 2017
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Silver-doped hydroxyapatite for formaldehyde determination by digital-image colorimetry.
Uma Pongkitdachoti1, Fuangfa Unob1
1Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand. fuangfa.u@chula.ac.th.
Analytical Methods : Advancing Methods and Applications
|February 15, 2022
Summary
A novel silver-hydroxyapatite material enables sensitive, trace-level formaldehyde detection. This method uses a colorimetric response visible in smartphone images, offering a promising tool for environmental monitoring.
Area of Science:
- Analytical Chemistry
- Materials Science
- Environmental Science
Background:
- Formaldehyde is a common pollutant requiring sensitive detection methods.
- Existing methods for formaldehyde detection can be complex or lack sensitivity for trace levels.
Purpose of the Study:
- To develop a novel, sensitive method for trace-level formaldehyde detection using silver-hydroxyapatite (Ag-HAP).
- To utilize a colorimetric approach based on Tollens' reaction for quantifiable formaldehyde analysis.
Main Methods:
- Synthesis and characterization of silver-hydroxyapatite (Ag-HAP) material.
- Application of Ag-HAP for formaldehyde detection via a surface-based Tollens' reaction.
- Quantification of color change using smartphone digital images and Image-J software.
- Optimization of reaction parameters including silver ion concentration, sodium hydroxide concentration, contact time, and sample volume.
Main Results:
- The Ag-HAP material exhibited a color change from off-white to yellow/brown, proportional to formaldehyde concentration.
- Optimized conditions yielded a working range of 15 to 200 μg L-1 for formaldehyde detection.
- The method demonstrated good accuracy (86–111% recovery) and precision (3–8% RSD) in water samples.
Conclusions:
- The developed Ag-HAP material provides a sensitive and accurate method for trace formaldehyde determination.
- The colorimetric approach using smartphone imaging offers a simple and accessible tool for formaldehyde analysis.
- This method shows significant potential for monitoring formaldehyde in environmental samples.

